I guess this started happening after we recently applied patches to update to 7.0.3. Only sites since then appear to be affected. Plesk is creating the file at_domains_index.html in the httpdocs directory of each created site, and the first document listed in the Documents tab in IIS for the site is at_domains_index.html. This means that if the file at_domains_index.html is present, it will be the default page. It appears to force a redirect to index.html. So, if a customer wants to use index.htm, default.aspx, whatever besides index.html, the site produces a 404 error because the at_domains_index.html file is redirecting to index.html. This is highly annoying!